This invention relates to a viewing system in general and more particularly to a system and method for improving the field of view of persons with reduced vision or those persons who are severely visually handicapped.
Unfortunately, there are many individuals in the world that have severe visual handicaps. Such individuals are partially sighted and require a large amount of magnification in order to seen and to read and in general to perform every day functions. To accommodate these individuals, various companies such as Designs For Vision, Inc., of 760 Koehler Avenue, Ronkonkoma, New York 11779, the assignee herein, supplies binocular or telescopic microscope devices which are used by such individuals to compensate for the visual defect. As such, these individuals may require full diameter telescopes which essentially are Galilean telescopes that are designed for distance tasks that are to be performed when the patient is stationary. As such, such devices are available in many different designs with powers of 1.7.times., 2.2.times., 3.0.times. and 4.0.times. or more.
While the full diameter telescope is generally used for distance tasks, it may be converted into a near optical aid with increased versatility by applying a reading cap over the front end of the telescope. Essentially, other patients may require bioptic telescopes which also provide the patient with the benefits of a telescopic system while still maintaining his mobility. These devices come in powers of 2.2.times., 3.0.times., and 4.0.times. and so on. Still other patients may require what is referred to as spiral expanded field prism telescopes. These telescopes give the patient maximum flexibility and use. With the larger fields, these units can be focused from true infinity to approximately 10 inches. The patient can adjust the working distance by focusing the objective lens. These are available in powers up to 10 times, as for example, 2.0.times. to 10..times..
In any event, a major problem that is encountered is that as the magnification is increased in any of these devices, the patient's field of view decreases accordingly. It is understood that all magnification reduces the field of view. For example, if a patient requires 14.times. magnification in order to read, the field of view is about the size of a thumbnail or about 1/2 inch.times.1/2 inch. This individual, in order to read, must hold the paper about 1inch from his optical aid. It is thus apparent that such individuals cannot easily view television or read without great difficulty.
As one can ascertain, in regard to the above-noted optical aids the field of view decreases in direct proportion to magnification. For example with the expanded field spiral focus telescope a patient will have a field of view with a 5.0.times. magnification of approximately 8 degrees. The field of view of an 8.0.times. magnification decreases to 4 degrees. As one can therefore ascertain, by such reductions in the field of view which are inherent in utilizing such optical aids, the patient is severely handicapped in regard to his field of view and thus cannot watch television or read without holding or positioning himself in front of the television or paper to enable him to accommodate the restrictive field of view while enabling him to accurately view the subject matter.
For a further explanation of such devices reference is made to a technical manual entitled Optical Aids for the Partially Sighted, published by Designs For Vision, Inc., the assignee herein. In regard to this manual which consists of approximately 70 pages there are detailed descriptions of each of the optical aids as described above together with the limitations on the field of view which as indicated above varies according to the magnification required by the patient.
In any event, the prior art is aware of problems regarding the limited field of view and regarding in general the problems of the visually handicapped. As such, there has been a host of articles and various other documents present in the prior art which attempt to teach the partially sighted to utilize optical aids such as binoculars and telescopes in order to enhance their visual problems. For example, see an article entitled "Binoculars: A Long Ignored Aid For The Partially Sighted", published in the American Journal of Optometry and Physiological Optics, Volume 51, September 1974 by Samuel M. Genensky, The Rand Corporation, Santa Monica, Calif., pages 648-673.
This article advises the partially sighted in the use of visual aids which are ordinary binoculars and telescopes to enable such visually handicapped persons to view various objects such as street signs and so on.
Other U.S. Patents such as U.S. Pat. No. 3,171,884 which issued on Mar. 2, 1965 to J. R. Miles and is entitled A MAGNIFIER HAVING A RELATIVELY LARGE FIELD AND EYE RELIEF also shows various optical systems in order to enable visually handicapped persons to view with more proficiency. As one will ascertain, the problem with the use of such optical aids as conventional telescopes or binoculars is that such devices also severely limit the field of view. Thus, as explained in such articles, a handicapped user who uses and requires a microscopic aid can only view an object if the object is held very close to his eyes as for example 1/2 inch or so. In these articles as for example the above-noted article of Genensky, it is indicated that the visually handicapped user first sight the object or area that he wishes to view along the upper edge of the center line of the binoculars or along the upper edge of one of its optical trails or paths. Then the handicapped user without moving this head is to bring the binoculars up to his eyes. Usually this procedure guarantees that at least part of the object area of interest would be in the field of view of the binoculars or very close to that field of view.
Thus, as one can ascertain from the various prior art, a person wearing a microscopic optical aid cannot function to utilize binoculars or telescopes to any great degree. The person cannot view the distanct object unless it is held approximately 1/2 inch away from his eyes or from the microscopic aid. In any event, if he could do this, all he would receive is part of the object or area of interest. In any event, in order to view any distant object using conventional telescopes or microscopes, the person must constantly scan the object or move the additional aids such as the binoculars or telescopes. This is also clearly described in the above-noted article or in various other references.
It is therefore an object of the present invention to provide a viewing system and method of viewing to enable visually handicapped individuals to watch television in a convenient manner at a reasonable distance from the television screen.
It is a further object of this invention to allow a visually handicapped user to view a distant object which object is completely reduced in regard to image size so that the complete object can be reviewed totally in a reduced size.
As will be explained, in the applicant's device, there is no increase in the visual angle but there is an actual decrease in the complete size of the remote image.
It is a further object of this invention to provide apparatus which is placed in front of a distant object to enable a visually handicapped user to view a complete image of the distant object at a reduced size with optimum resolution.
It is a further object of the present invention to enable a person who is visually handicapped and who requires an optical aid to view the complete distant object by taking the distant object such as a television screen and minifying the same to fill the effective field of view of the handicapped person as caused by the optical aid as worn by that person.
These and otehr objects of the invention will become more apparent when reference is made to the following specification.